Electronic devices, including portable electronic devices, have gained widespread use and may provide a variety of functions including, for example, telephonic, electronic messaging and other personal information manager PIM application functions. Portable electronic devices include, for example, several types of mobile stations such as simple cellular telephones, smart telephones, wireless personal digital assistants PDAs, and laptop computers with wireless 802.11 or Bluetooth capabilities.
Portable electronic devices such as PDAs or smart telephones are generally intended for handheld use and ease of portability. Smaller devices are generally desirable for portability. A touch-sensitive display, also known as a touch screen or touchscreen display, is particularly useful on handheld devices, which are small and have limited space for user input and output. The information displayed on the touch-sensitive displays may be modified depending on the functions and operations being performed. With continued demand for decreased size of portable electronic devices, touch-sensitive displays continue to decrease in size.
Portable electronic devices can typically individually control power supplied to different components of the device in order to save power and increase battery. For example, in a full power mode, the main components of the portable electronic device are supplied with power and are in an active state. In a sleep mode, one or more components of the portable electronic device are not supplied with power, or are supplied with reduced power, and are in an inactive state.
Portable electronic devices can be transitioned from full power mode to sleep mode, or from sleep mode to full power mode using a soft power control system. For example, when the portable electronic device is in full power mode, a signal from an input key or a system software time-out signal will transition the portable electronic device to sleep mode, or vice versa.